Sterilization control means



June 17, 1969 J Y. I 3,450,489

I STERILIZATION CONTROL mamas Filed .July 25, 1966 7 Sheet AMPLIFIER TIMER v INVENTOR. Jamefi P 7 61 Y W M k-Qud H 7 OIQNEYS June 17,1969 J, P, AY 3,450,489

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AMPLIFIER TIMER POWE ENE?GY D/RADIATING MEANS s lCvNAL. ENERGY CONTROL GENERATOR L055 7 UNIT MEASURE 7g 7 INVENTOR. James P fby M km,

I HTTOF/VEVS United States Patent 3,450,489 STERILIZATION CONTROL MEANS James P. Fay, 18 France St., Norwalk, Conn. 06851 Filed July 25, 1966, Ser. No. 567,415

Int. Cl. A61d 3/02 US. Cl. 21-93 11 Claims ABSTRACT OF THE DISCLOSURE This invention relates to the sterilization of articles wrapped in sealed packages or bundles.

Heretofore articles have been wrapped and sealed in bundles or packages and have been placed in sterilizing chambers and subjected to a predetermined heat for a controlled time in order to sterilize the articles. However, there has been no practical way, short of breaking the seal of the packages, to determine when the articles in the package reach a predetermined temperature at which the sterilizing process starts and when the timing operation should begin. Thus, many articles in said bundles may not have been thoroughly sterilized since they may not have been at the required temperature for the required time.

The present invention overcomes this difliculty by providing a device which is sealed in the bundle or package with the articles and which is operative upon the articles in the bundle or package reaching a predetermined temperature to produce a signal or condition which is detected by means external to the bundles or packages to control the sterilizing operation to insure the proper sterilization of the articles.

This is accomplished by embedding within the sealed bundle or package to be inserted in the sterilizing chamber a heat-responsive signal generator or producer which is responsive to the temperature of the articles in the bundle or package to produce or create a signal when said articles reach a required temperature. The signal can be preferably a sound vibration or an electrical signal or the like, and a detector or pickup externally of the bundle will be activated by the signal to start a timer or other means for controlling the sterilizing operation by the sterilizing device thus insuring that the articles be properly and adequately sterilized. The detector or pickup may be located within, or on the outside of, the sterilizing chamber.

A feature of the invention resides in the fact that the signal device for producing or creating a control signal may be inexpensive so as to be thrown away when the bundle is used and thus eliminate the need of retrieval thereof.

Other features and advantages of the invention will be apparent from the specification and claims when considered in connection with the accompanying drawings in which:

FIGURE 1 shows a housing forming a sterilizing chamber with the portion of the door cut away showing the bundle therein having a signal device included therein.

FIG. 1A is a diagrammatic view of the sterilizer showing the detector means disposed outside of the sterilizing chamber.

FIG. 2 is a longitudinal sectional view of one form of signal device.

FIG. 3 is a longitudinal sectional view of another form of signal device.

FIG. 4 is a longitudinal sectional view of a whistletype signal device.

FIG. 5 is a longitudinal sectional view of a radio frequency signal device.

FIG. 6 is a diagrammatic view of another type of electrical signal device.

FIG. 7 shows another form of the invention in which a short tube of metal capable of changing length is responsive to change in temperature.

FIG. 8 shows another form of detector means.

As shown in FIG. 1, a housing 10 is provided which forms a sterilizing chamber 11 which is closed by a door 12 hinged thereto and is capable of providing a sterilizing atmosphere for sterilizing one or more bundles 13 disposed therein.

The bundles comprise a plurality of articles A which are to be sterilized and which are wrapped and sealed in paper or the like material 14. Within at least one of the bundles is provided a signal producer or device 15 which, upon the articles reaching a predetermined temperature in the bundle, will produce a signal which is picked up by a detector or pickup means 16. This means is a usual transducer for converting the signal into a control current or pulse fed to an amplifier and timer unit 17 for regulating the power source 18 for the sterilizing chamber for controlling the sterilizing operation. Thus, it will be seen that when the articles reach a predetermined temperature at which sterilization should start, the signal device will produce a signal or condition which is detected and picked up by the detector 16 and is operative to start the timing of the sterilizing operation, thus insuring the full sterilization of the articles without the necessity of testing by breaking the seal.

Preferably, the signal devices 15 are of an inexpensive character so that they may be retained within the package and the package maintained sealed and sterile until ready for use. This is of particular importance in hospitals where many of the articles, such as linens, instruments and the like, must be sterilized. This will insure proper sterilization of the linens, instruments and the like which are maintained in a sterile condition until ready to use. When the bundle is used, the signal device being of an inexpensive nature can be thrown away and a retrieval of these signal means made unnecessary.

In the form of the invention shown in FIG. 1, the pickup device 16 is disposed within the sterilizing chamber. However, if desired, the detector 16a can 'be positioned externally of the chamber as shown diagrammatically in FIG. IA.

The signal devices can be of various characters. For example, as shown in FIGS. 2, 3 and 4, the signal device emits a sound which can be readily detected and converted to control the amplifier and timer unit 17.

In the form of the invention shown in FIG. 2, a disk 20 is mounted to slide on a rod 21 carried by a capsule type casing 22. The disk 20 is maintained in'the position of FIG. 2 so as to hold a spring 23 in a compressed condition by means of a heat-responsive alloy member 24, connecting the disk 20 to the rod or shaft 21. When the articles in the bundle reach a predetermined temperature, the material of the heat-responsive alloy member 24 will melt and the spring will cause the disk to slide in the direction of the arrows in FIG. 2 over the roughened surfaces 25, 26 of the rod and interior surface of the capsule, thus producing a sound which can be readily picked up and detected by the detector mechanism.

In the form of the invention shown in FIG. 3, a capsule 30 encloses a torsion spring 31 and a disk 32 within the capsule. As shown, one end 31a of the spring is connected to the disk 32 and the other end 31b passes through the capsule. The torsion spring is wound up and held in its tensioned position. While this may be done with a bimetal detent, it is herein illustrated as being held by a mass of heat-responsive material or alloy 34. When the device is positioned in a bundle to be sterilized and the articles reach a predetermined temperature, the heat will cause the heat-responsive material or alloy to release, rotating the disk within the capsule and thus producing between the walls of the capsule and the edge of the disk a vibration or sound which is picked up and detected by the detector means.

In the form of the invention shown in FIG. 4, there is provided a whistle 40 having at the inner end thereof a narrow passage 41 connected to a bulbous portion 42 secured thereto. Within the bulbous portion there is disposed a gas forming high volatile heat actuating material 43 such as alcohol or the like having a boiling point lower than water. The passage 41 to the whistle is sealed by a heat-responsive alloy so that when the articles in the bundle become heated to the required temperature, the material 43 in the bulb will have expanded and become a gaseous material, and upon the softening of the plug or seal 44 in the reduced portion, the material from the bulb will rush through passage 41 to the whistle and produce a required whistle sound which can be detected by the detector means.

It will be noted that it is preferred in the foregoing three forms of the invention that the alloy material be retained in the capsule or whistle and not contaminate the articles.

In the form of the invention shown in FIG. 5, a plastic case 50 is provided with a bimetallic disk-shaped element or snap disk 51 which closes the same. Within the case is a metal block 52 and a piezoelectric element 53, such as barium titanate, which is positioned between the metal block 52 and the bimetal snap disk 51. An inductor coil 54 connects the snap disk to the metallic block. The bimetal element in combination with the metal block forms a capacitor in which the barium titanate forms a port-ion of the dielectric. This capacitor with the inductance can resonate at a desired frequency. The popping of the bimetal disk when the articles in the bundle reach a predetermined temperature excites the piezoelectric element and produces a momentary charge across the capacitor which initiates a damped oscillation whose amplitude decreases incrementally and which oscillation can be picked up by the pickup means for controlling the amplifier and the timer unit.

Another form for producing an electrical signal is shown in FIG. 6 in which a bar magnet 60 is urged by a spring '61 to rotate but is prevented from rotating by a bimetallic stop strip 62. When the desired temperature is reached, the bimetallic latch flexes and releases the magnet which revolves within a pole piece 63. A voltage is induced in a winding 64 carried by the pole piece and this induced voltage may be used to power a transmitter for a period or may be the output signal voltage which is detected by the detector means or pickup.

In another form of the invention the signal producing means comprises a passive device which is disposed within the package and will absorb energy at a particular frequency. In this form of the invention the detector means external of the package will produce energy at a particular frequency, which energy will be absorbed by the device when the conditions in the device change to a particular degree in accordance with the temperature of the articles in the package. This change of condition by which the energy is absorbed is detected by the detector means and is used to initiate the timing cycle. While the device can be a short rod, in the illustrated form of the invention it comprises a short length of metal tube 70, as shown in FIG. 7, which is of a character to change in length and energy absorbing ability with a change in temperature. When the articles A in the package reach a predetermined temperature, the tubing will have expanded to a predetermined degree and the tuned pipe formed thereby will become resonant and absorb energy produced by the detector means 16a and transmitted at a predetermined fre quency.

In this form of the invention the detector means 1617, as shown in FIG. 8, comprises a signal generating unit 72 which is connected to an energy radiating means disposed externally of the bundles but in energy transferring relation with respect to the device 70 within the bundle. The signal generating means is also connected to an energy loss measuring device 74 which measures the loss of energy in the signal generating means when the device 70 is in resonant relation with the signal radiating means. The loss measuring device then produces the control signal for controlling the timing unit 17 and the power 18.

All of these devices are examples of low cost signal producers or creators which can be used to provide a signal upon the articles sealed in each package or bundle reaching a predetermined temperature to control the timing of the sterilizing operation and which, because of their inexpensive nature, can be readily discarded when the bundle or package of sterilized articles is used.

The present invention thus insures proper sterilization of the articles without the necessity of breaking the seal of the package to determine the condition of the articles within the package.

Variations and modifications may be made within the scope of the claims and portions of the improvements may be used without others.

I claim:

1. In a device tor sterilizing articles, a housing forming a sterilizing chamber having means for receiving wrapped bundles of articles to be sterilized, said chamber having means, including a controller therefor, for producing a sterilizing condition in the chamber, a sealed, wrapped bundle of articles having a thermal-responsive signal producing means enclosed within the bundle, said bundle being free of external connections and disposed in the sterilizing chamber, said signal means operating upon the attainment of a predetermed temperature within the sealed bundle to produce and transmit a control signal from the bundle, and detector means operatively associated with said controller and disposed externally of the bundles for picking up said signal for controlling the sterilizing operation to insure thorough sterilization of the articles in said bundle.

2. The device as defined in claim 1 wherein the signal producing means produces a sound signal.

3. The device as defined in claim 1 wherein the signal producing means produces an electrical signal.

4. The device as defined in claim 1 wherein the lastnamed means is disposed within the sterilizing chamber.

5. The device as defined in claim 1 wherein the lastnamed means is disposed outside the sterilizing chamber.

6. The device as defined in claim 1 wherein the signal producing means comprises a disk disposed within a capsule having roughened surfaces for longitudinal movement thereover, spring means for moving the disk, and heat-responsive means for holding the disk against movement by said spring means until a predetermined temperature has been attained in said capsule, whereupon the disk is released to move over the roughened surfaces and produce sound vibrations.

7. The device as defined in claim 1 wherein the signal means comprises a disk disposed within a capsule for rotary movement therein, a torsion spring within the capsule for rotating the disk, and heat-responsive means for holding the disk against movement bysaid spring until a predetermined temperature has been attained in said capsule, whereupon the disk is released and rotated within the capsule to produce sound vibrations.

8. The device as defined in claim 1 wherein the signal means comprises a whistle device having a chamber connected thereto having a volatile material sealed therein by a heat-responsive sealing means, such that when the signal means is heated to said desired temperature, the seal is destroyed and the volatile material expands and passes through the whistle to produce a sound signal.

9. The device as defined in claim 1 wherein the signal producing means comp-rises a rotary electrical current generator and means for rotating the generator, a heatresponsive means for preventing the rotation thereof, said last-named means being released upon attainment of a predetermined temperature in the bundle whereby the rotary generator produces an electrical signal.

10. The device as defined in claim 1 wherein the signal means comprises a radio frequency generator having a heat-responsive control for causing the generation of a radio frequency signal upon reaching a predetermined temperature in the bundle.

11. The device as defined in claim 1 wherein the signal producing means comprises a device having the characteristic of changing the condition thereof in response to the temperature of the articles in the bundle to change the energy absorbing character thereof and wherein the means associated with the controller includes a timer unit and detector means to detect the energy absorption for controlling said timing of the sterilizing operation.

References Cited UNITED STATES PATENTS 2,112,639 3/1938 Underwood 2198 2,208,552 7/1940 Walter 2198 3,093,449 6/ 1963 Kotarski et a1 2156 XR FOREIGN PATENTS 887,848 1/ 1962 Great Britain.

MORRIS O. WOLK, Primary Examiner. BARRY S. RICHMAN, Assistant Examiner.

US. Cl. X.R. 

